An element E loses one and two particles in three successive stages. The resulting elemenl wiil be
an isobar of E
an isotone of E
an isotope of E
E itself
The electronic transitions from n = 2 to n= 1 will produce shortest wavelength in (where n = principal quantum state)
Li2+
He+
H
H+
What is the wavelength of an α-particle having mass 6.6 × 10-27 kg moving with a speed of 105 cms-1? ( h = 6.6 × 10-34 kgm2 - s)?
2 × 10-12 m
3 × 10-10 m
1 × 10-10 m
2 × 10-10 m
C.
1 × 10-10 m
Since,
= 1 × 10-10 m
1 × 10-10 m is the wavelength of an α-particle having mass 6.6 × 10-27 kg moving with a speed of 105 cms-1.
The energy of an electron is the 3S orbital ( excited state) of H- atom is
-1.5 eV
-13.6 eV
-3.4 eV
-4.53 eV
Which transition in the hydrogen atomic spectrum will have the same wavelength as the transition will have the same wavelength, n = 4 to n = 2 of He+ spectrum?
n = 4 to n = 3
n = 2 to n = 1
n = 4 to n = 2
n = 3 to n = 1
The radius of the first Bohr orbit of hydrogen atom is 0.529 Å. The radius of the third orbit of H+ will be
8.46 Å
0.705 Å
1.59 Å
4.29 Å
The uncertainties in the velocities of two particles A and B are 0.05 and 0.02 m/s-1 respectively. The mass of B is five times to that of mass A. What is the ratio of uncertainities in their positions?
2
0.25
4
1
For a crystal, the angle of diffraction (2 θ) is 90° and the second order line has a d value of 2.28 Å. The wavelength (in Å) of X-rays used for Bragg's diffraction is
1.612
2.00
2.28
4.00
The wavelength of a spectral line emitted by hydrogen atom in the Lyman series is . What is the value of n2? ( R= Rydberg constant).
2
3
4
1